The use of autonomous underwater vehicles (AUV) is expanding exponentially for a wide range of undersea mapping, monitoring and surveillance missions. As is the case for manned submarines, the sensing capabilities of AUVs are in general limited to acoustic sensing using onboard sonar systems, such as side scan or synthetic aperture sonars for seabed mapping, multi-beam sonars for bathymetry assessment, or forward looking sonars for obstacle avoidance or feature search. FIG. 1 is a prior art schematic diagram illustrating AUVs 2, 4 performing surveys in littoral environments with heavy ship 10, 12 traffic.
With the exponential increase in use of AUVs for both military and civilian applications over the last couple of decades, there has been a growing list of incidences involving destruction or heavy damage as a result of collisions between AUVs and surface craft. Specifically, there are several historical examples of accidents involving collision between AUVs and surface vessels, in particular in shallow littoral regions with heavy surface traffic, such as shipping channels, with the almost universal result of a total loss of the small AUVs. Due to extreme cost associated with AUVs, it is important to prevent damage and/or total loss.
In contrast, manned submarines have a variety of passive and active sonars available to the operators, and experienced sonar operators are extremely capable of identifying the sound signatures of approaching surface vessels, and estimate their speed, location, and heading, enabling the submerged platform to take action to avoid a collision. Unfortunately, these advantages are not available in AUVs.
Thus, a heretofore unaddressed need exists in the industry to address the aforementioned deficiencies and inadequacies.